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12-24-2009, 04:55 PM   #16
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I put it down to PLBV (problem lies behind viewfinder). :ugh:

Can't focus right... complain
Don't read manual and can't work out camera functions... complain
Can't grip the camera correctly (aka poor technique)... complain
Put crappy batteries... complain
Can't shoot for nuts... complain
The list goes on...

12-24-2009, 07:26 PM   #17
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QuoteOriginally posted by creampuff Quote
I put it down to PLBV (problem lies behind viewfinder). :ugh:

Can't focus right... complain
Don't read manual and can't work out camera functions... complain
Can't grip the camera correctly (aka poor technique)... complain
Put crappy batteries... complain
Can't shoot for nuts... complain
The list goes on...
Then youīre clearly not paying attention. ;-)

The only thing in that list thatīs relevant to the issue being discussed is the "poor technique" jab. I have stated several times that my handholding technique is perfectly fine, that I have shot with numerous SLRs and gotten sharp results often as low as 1/30th without SR, and I get sharp shots both above and below the problem range with SR. It is only in that range of shutter speeds using the K-x with SR activated that a problem occurs. With the SR deactivated the problem does not occur. With the K20D with SR activated the problem did not occur. With the 40D and E-330 and OM2 and K1000 with no SR the problem did not occur.

The logical conclusion is a malfunction of the SR system in at least some samples of K-x. Your post is potentially offensive (I donīt see the point in getting personal over the internet, but others feel differently) and adds nothing to the thread.
12-24-2009, 08:28 PM   #18
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QuoteOriginally posted by er1kksen Quote
Then youīre clearly not paying attention. ;-)

The only thing in that list thatīs relevant to the issue being discussed is the "poor technique" jab. I have stated several times that my handholding technique is perfectly fine, that I have shot with numerous SLRs and gotten sharp results often as low as 1/30th without SR, and I get sharp shots both above and below the problem range with SR. It is only in that range of shutter speeds using the K-x with SR activated that a problem occurs. With the SR deactivated the problem does not occur. With the K20D with SR activated the problem did not occur. With the 40D and E-330 and OM2 and K1000 with no SR the problem did not occur.

The logical conclusion is a malfunction of the SR system in at least some samples of K-x. Your post is potentially offensive (I donīt see the point in getting personal over the internet, but others feel differently) and adds nothing to the thread.

I have to agree with you er1kksen.

The link I posted above (/\) is from a very experienced Pentax shooter/imager.
From what i'm seeing it must be a lag in the SR on some of the KX kits.
12-24-2009, 08:35 PM   #19
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QuoteOriginally posted by UnknownVT Quote
This got me concerned enough to do my own tests -
out of 8 shots at 1/100sec with K-x SR on - NONE showed any blur -

overall shot with crop area shown


100% actual pixel crop (EXIF still attached) -


sorry about the noise/grain -
it's not particularly bright out today and to get 1/100sec the ISO was 3200 -
and it's cold out too, so I am not exactly the most "still" I could be......
So although this is casual/ad-hoc, it is pretty "severe"/worst case - for me -
so for my K-x there does not seem to be any problem with the SR at 1/100sec.

EDIT to ADD -

I thought I'd also shoot at 1/160sec SR on - out of 6 shots - again NONE showed blur.
The light had dropped even more so to shoot 1/160sec at ISO3200 meant my shots were actually underexposed - all I did was to increase brightness PP -


So at 1/160sec also my K-x with SR does not seem to show any blur problems......
You got a good one VT!
I'm starting to think that there just might be some bad kx examples out and about.

12-24-2009, 08:50 PM   #20
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Another thread you might want to paruse.

K-x SR delay and performance: Pentax SLR Talk Forum: Digital Photography Review
12-25-2009, 04:09 AM   #21
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QuoteOriginally posted by Raybo Quote
Unfortunately, it still happens when I wait for the SR indicator to light up fully.

Iīm out for a bit. Machu Picchu time!
12-25-2009, 08:15 AM   #22
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QuoteOriginally posted by er1kksen Quote
Unfortunately, it still happens when I wait for the SR indicator to light up fully.
When you get to somewhere where you can post your examples - please show us the problem (with EXIF?)

QuoteOriginally posted by er1kksen Quote
Iīm out for a bit. Machu Picchu time!
Now I'm jealous - have a great Christmas on Machu Picchu -
take plenty of pictures (isn't that a given? )
but please use the settings that you know don't have the SR problem
12-28-2009, 07:29 AM   #23
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"I put it down to PLBV (problem lies behind viewfinder)"

Sure, easy enough to dismiss if you are inclined. Anyway, count me as another one who knows his way around a dSLR/SLR [FM2, D40, D200, K10D] and who came out very much non-plussed with the K-x ... and I really wanted to love it.

Bad technique can explain a few shots here and there, and that's why posting samples is futile as any such posts can easily be dismissed. When you are sitting at a PC with 100's or 1000's of photos taken and forming an opinion, though, it's very different. Likewise bad lenses, buggy SR, poorly damped mirrors ... all kinds of explanations are available, but sooner or later statistics will out.

The conspiracy theories of industrial sabotage are equally crude, too. No need to play up to the perception that Pentax users recruit heavily from the tinfoil hat brigade.

12-28-2009, 09:06 AM   #24
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K-x replies

QuoteOriginally posted by rjm Quote
The conspiracy theories of industrial sabotage are equally crude, too. No need to play up to the perception that Pentax users recruit heavily from the tinfoil hat brigade.
My entire purpose in making that observation as to promote substantive replies such as Er1kksen has made, and to discourage "me too" additions to the thread(s) that add no further value.

If replies contain substantive information, as this POST progresses, enough information should emerge to establish an hypothesis for what is actually going on with the K-x; or nothing will emerge.

Adding "Pile-on" replies is not helpful identifying the problem and is potentially harmful is there is none.
12-28-2009, 02:03 PM   #25
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We have obviously heard from experienced users about a possible SR problem -
I would say that alone adds some credence to this possible issue -
just because I don't have it with my one sample of the K-x
does not mean it may not exist.

There is enough smoke out there that we should try to get to the bottom of this.

I noticed in dpReview -
from: Pentax K-x Review: 13. Performance: Digital Photography Review
" Image stabilization delivers visible results but they are not as impressive as on some of the other systems that we've seen. It generates an advantage of approximately one stop. It appears to be slightly more efficient at very slow shutter speeds where it significantly increases your chances of getting a usable shot and therefore certainly provides a real benefit in many shooting situations. "

It appears dpReview only see about a one stop advantage -

I have done my own trials under my kind of shooting I seem to be able to get consistently about 2.5 stops to 3 stops advantage with my one sample of the K-x - depending on whether I rest my arms/elbow on something or not (respectively) -

I shoot mostly under lower light and pretty trying/demanding conditions often having to shoot slower than 1/15sec to as low as 1/4sec ...
and although some shots do show subject movement - I can check stationary objects and I can see that mostly the SR works fine for me under those trying circumstances.......

So from that long story - maybe there is something about the Pentax in-body SR that may give some rise to speculation that it may not work properly under some specific circumstances?
12-28-2009, 03:01 PM   #26
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QuoteOriginally posted by Alfisti Quote
I know, I know, it's totally nuts. I seriously doubt it myself but in one day I have seen three guys complaining of the same thing and they don't appear to be all in cahoots. Kinda weird though huh?
A review of many recent images shot with my K-x with SR on at or around the "problematic"range of shutter speeds reveals no such problems with my camera as I mentioned in the other thread.

The issue could be a hardware problem on some units I guess but a rough analysis of the images presented as problematic lead in two directions, one set at least displayed lateral offset and the others complained of general blur.

Given that both the mirror and shutter create forces in virtually only in the vertical plane it's unlikely that these are the physical triggers for poor-performance of the SR system.

Also the SR system "gyro" sensors have a far slower response than many people seem to give them credit for (assuming that they are the same units as used in the K10/20). These devices sense at a maximum angular velocity of +/-300 degrees/second. Spin your hand, it's pretty slow compared to the flick of a mirror.

In any case if general focus issues and excessive unsteadiness can be ruled out one would assume that if it's a problematic response of the SR system then it would likely not be proportional (ie not be related to lens FL)? An interesting test for anyone who's camera is suffering this problem would be to see if approximately the same pixel level blur is produced using an ultra-wide vs a medium tele. If the ultra wide is showing the same amount of blur I would definitely be blaming the SR system.

Without more samples and data we can only speculate (which is entertaining but not always helpful). Anyone with a problem camera care to get a bit more scientific about it?

Cheers,
12-28-2009, 03:13 PM   #27
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QuoteOriginally posted by Alfisti Quote
I know, I know, it's totally nuts. I seriously doubt it myself but in one day I have seen three guys complaining of the same thing and they don't appear to be all in cahoots. Kinda weird though huh?
Another related thread, includes a potential "fix"

K-x malfunction, any similar experience?: Pentax SLR Talk Forum: Digital Photography Review
12-28-2009, 10:33 PM   #28
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my k20d's SR function 'broke' was sent back and they replaced it.

Pretty much did what is shown here, added shake

It would add shake to anything below 1/500 ish
12-29-2009, 06:29 AM   #29
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QuoteOriginally posted by UnknownVT Quote
Now I'm jealous - have a great Christmas on Machu Picchu -
take plenty of pictures (isn't that a given? )
but please use the settings that you know don't have the SR problem
Thanks for the warm wishes, christmas was great though we didnīt get to visit the *actual* site of machu picchu (a whole story in itself). We were able to vew it from another excellent vantage point, however, rendering the tourists nearly invisible, and... shock and awe! I wasnīt watching the shutter speed at one point, and it found its way to 1/160... in a burst of four shots, one of them actually looked sharp on the K-x screen. :-) That doesnīt garauntee critical sharpness in RAW, but itīs nice to know that once in a while the SR in my K-x is lazy enough to let me get a sharp shot in that range. ;-) Always pretty reliable in low light, though, which is where it counts. Iīll probably leave it off in good light from now on.

QuoteOriginally posted by distudio Quote
A review of many recent images shot with my K-x with SR on at or around the "problematic"range of shutter speeds reveals no such problems with my camera as I mentioned in the other thread.

The issue could be a hardware problem on some units I guess but a rough analysis of the images presented as problematic lead in two directions, one set at least displayed lateral offset and the others complained of general blur.

Given that both the mirror and shutter create forces in virtually only in the vertical plane it's unlikely that these are the physical triggers for poor-performance of the SR system.

Also the SR system "gyro" sensors have a far slower response than many people seem to give them credit for (assuming that they are the same units as used in the K10/20). These devices sense at a maximum angular velocity of +/-300 degrees/second. Spin your hand, it's pretty slow compared to the flick of a mirror.

In any case if general focus issues and excessive unsteadiness can be ruled out one would assume that if it's a problematic response of the SR system then it would likely not be proportional (ie not be related to lens FL)? An interesting test for anyone who's camera is suffering this problem would be to see if approximately the same pixel level blur is produced using an ultra-wide vs a medium tele. If the ultra wide is showing the same amount of blur I would definitely be blaming the SR system.

Without more samples and data we can only speculate (which is entertaining but not always helpful). Anyone with a problem camera care to get a bit more scientific about it?

Cheers,
The problem images Iīm getting display definite motion blur (I suspect thatīs what you mean by lateral offset). "General blur," when it occurs, is generally my fault. No excuses there.

I would be happy to (and intend to) get a bit more scientific about it once I have the opportunity to do so (as noted, Iīm pretty far from home atm). The only thing I may not be able to help with are the ultrawide vs. tele tests, since my widest is 18 and my longest is 55. I suspect you might not be able to get a meaningful result out of such a test, however, since the only consistent thing about the blur is that itīs blurred. Sometimes itīs just a little bit, sometimes itīs significant. Once in a blue moon (like the machu picchu shot I mentioned) it doesnīt even occur.

In the meantime, anyone reading this thread should NOT be considering this a reason not to get a K-x. Most units seem to be unaffected, and you really shouldnīt need SR for most focal lengths at 1/100-1/200 anyway (learning good technique is far more beneficial in the long run than having SR). The images this little camera puts out are fantastic.
12-29-2009, 07:19 AM   #30
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QuoteOriginally posted by Alfisti Quote
I know, I know, it's totally nuts. I seriously doubt it myself but in one day I have seen three guys complaining of the same thing and they don't appear to be all in cahoots. Kinda weird though huh?

https://www.pentaxforums.com/forums/pentax-dslr-discussion/84153-k-x-soft-images-2.html

https://www.pentaxforums.com/forums/pentax-dslr-discussion/84344-k-x-throughl...pointed-3.html

p.s the first thread has one guy mention the problem an danother with soft images in the same shutter speed range without saying he thinks that's the issue. Then the guy in the second thread ..... really, why so soft?
QuoteOriginally posted by DonP Quote
It's not a fabricated issue for me and I'm not a noob with an slr in my hand. I've been shooting film slr's since '71 and digital since the D40 came out. I AM new with the K-x and haven't ruled out pilot error with the camera. But I do have a definite softness in the shutter range I mentioned above and will get to the root cause. If it's me - I'll change my methods. If not, I'll shoot at slightly higher or slower speeds. No biggie.
Another thread to check....
K-x malfunction, any similar experience?: Pentax SLR Talk Forum: Digital Photography Review
Possible reason: Pentax SLR Talk Forum: Digital Photography Review

Seems his problem is if the camera is in a vertical position... any confirmation?
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